Then I turned the 15 mm OD silver steel spigot to 4 mm and fitted that to ball.

Next step was to mount it to square ER32 block. Only consideration was how much to stick it out. Obiviously I don't want square block ER nut and mill ER25 chuck nut to collide way before adequate length is milled.

Because I don't need to use round 8 mm mount, I could modify measuremets a little out of 10x10mm, to 9,5x11 mm, which gives me a little more margin on next step.

I much anticipaed milling the 3 mm oval ....I had ONE 3 mm carbide mill and that has 8 mm cut length. See the problem there when it has to pierce nearly 10 mm.

I drilled the 3 mm hole with carbide drill and expanded the hole 2 mm c-c. I set right table hard stop before drilling and left table stop with 2 mm feeler gauge stack. I advanced mill down in 0,5mm steps and slot in X-axis.

Drilling and tapping went without problems. I tapped both holes trough....I needed to try knobs before comitting to which directions to make clearance holes.

I made it to these measures, but in the end it came out slightly oversize....I milled it to dimenssion and tried the DTI, it would not fit, enlarged the slot for 0,25 and it was still sticky, removed all the burr and it was loose....Compared it chinese holder and Swiss and then it did not feel that bad any more.

I shoudl have used pins to measure the dovetail...tired it after it was finished and it showed that when right pin size is sellected it gives pretty good indication of the dove tail dimension.

Sawing was a balancing act. 80 mm OD 0,8mm saw arbor has 3 mm portrusion at the bottom. I.E. blade will clear the vise bit over 3 mm - that is the blade offset from the vise jaw and leaves little to mount.